1. Field of the Invention
This invention relates to a resin composition for encapsulating a semiconductor chip and a semiconductor device therewith.
2. Description of the Related Art
Recently, epoxy resin compositions have been predominantly used for encapsulating a semiconductor chip because of their good balance among productivity, a cost and reliability. Along with reduction in a size and a thickness in a semiconductor device, an epoxy resin composition for encapsulating with a lower viscosity and higher strength has been needed. Furthermore, in terms of environmental concerns, it has been increasingly needed to make a device fire-resistant without a fire retardant such as Br compounds and antimony oxide. From such a situation, there has been recently a distinctive tendency to employing a less viscous resin and adding more inorganic fillers to an epoxy resin composition.
As a new trend, a semiconductor device has been more frequently mounted using an unleaded solder with a higher melting point than a conventional solder. For applying such a solder, a mounting temperature must be higher by about 20° C. than a conventional temperature, and thus a mounted semiconductor device becomes considerably less reliable than a device of the related art. Therefore, the need for improving reliability in a semiconductor device by providing a higher-level epoxy resin composition has increasingly become stronger, which further accelerates reducing a resin viscosity and increasing the amounts of inorganic fillers.
As well-known technique, a low viscosity and a high flowability during molding can be maintained by using a resin with a lower melt viscosity (see, Japanese Patent Application NO. 1995-130919 (pp. 2-5)) or by surface-processing inorganic fillers with a silane coupling agent for increasing the amounts of the inorganic fillers (see, Japanese Patent Application NO. 1996-20673 (pp. 2-4)).
However, any of these methods cannot simultaneously meet all requirements of crack resistance, higher flowability and fire resistance. Thus, there has been needed technique in which a resin with improved crack and fire resistance can be used and the amounts of inorganic fillers can be increased to sufficiently improve reliability without deterioration in flowability or curing property.